负载离子液体调节MCM-36上异丁烷和1-丁烯的相对吸附量

通过接枝将离子液体1-烷基-3-(三乙氧基硅丙基)咪唑硫酸氢盐(烷基:甲基、乙基、丁基)在MCM-36分子筛表面进行负载改性,通过~1H-NMR、FT-IR、XPS、TGA、XRD、SEM、BET和正丁胺回滴法等对改性的MCM-36(MCM-36-ILs)进行表征。结果表明酸性离子液体通过化学作用在MCM-36表面进行负载;负载离子液体的催化剂可以在350℃以下稳定存在而不分解;负载离子液体能增加固体酸催化剂表面的酸量,但比表面积和平均孔容有一定程度的降低。Sip模型能很好描述异丁烷、1-丁烯在MCM-36负载离子液体前后固体酸催化剂上的平衡吸附量。异丁烷、1-丁烯在离子液体改性的MCM-36上的吸附性能与离子液体结构、离子液体负载量及催化剂表面特性等有关。负载酸性离子液体可以调节MCM-36上烷烯吸附比(n_I/n_O,相同压力下分子筛上吸附的异丁烷和1-丁烯的物质的量之比)。经1-乙基-3-(三乙氧基硅丙基)咪唑硫酸氢盐负载改性的MCM-36具有较好的烷烯吸附比调节性能,其表面的烷烯吸附比最高可以达到0.95,接近于烷基化反应所需的化学计量比。催化剂表面烷烯吸附比的改善有利于提高催化剂的性能和目标产物的选择性。     

苯酚在改性活性炭上的脱附活化能

探讨了金属离子改性活性炭对苯酚脱附活化能的影响.通过浸渍法分别将6种金属离子负载在活性炭表面,应用程序升温脱附技术测定了苯酚在系列改性活性炭上的脱附活化能,应用软硬酸碱理论分析和讨论了活性炭表面负载不同金属离子对苯酚脱附活化能的影响.结果表明,苯酚在A l(Ⅲ)/AC、Mg(Ⅱ)/AC、Fe(Ⅲ)/AC、Ca(Ⅱ)/AC上的脱附活化能高于其在原始活性炭上的脱附活化能,而它在Ag(Ⅰ)/AC、Cu(Ⅱ)/AC上的脱附活化能低于其在原始活性炭上的脱附活化能.根据软硬酸碱理论分类,苯酚属硬碱.在活性炭表面分别负载硬酸类金属离子Al3 、Mg2 、Fe3 和Ca2 ,会增大活性炭表面的局部硬酸度,提高对苯酚的吸附能力;Ag 属软酸,负载Ag 离子降低了活性炭表面的局部硬酸度,从而降低了其对苯酚的吸附能力;Cu2 离子属交界酸,负载Cu2 离子降低了活性炭表面的交界酸度,也在一定程度上减少了表面对苯酚的吸附能力.     

凹凸棒负载Zn-Al-La类水滑石对磷的吸附

采用共沉淀法合成凹凸棒(ATP)负载Zn-Al-La(LDHs)类水滑石纳米复合材料,通过扫描电镜(SEM)、傅里叶变换红外光谱(IR)、X-射线衍射(XRD)对复合材料的结构和形貌进行表征,发现层片状的水滑石覆盖在棒状的凹凸棒表面,凹凸棒成功负载水滑石形成ATP/Zn-Al-La复合材料.对影响复合材料吸附效果的主要因素(pH、吸附时间、温度、溶液浓度)及吸附过程的动力学进行研究.结果表明:磷酸根的吸附过程符合Langmuir等温吸附模型和准二级动力学模型,在40℃,溶液初始浓度为180mg/L,pH值为2,用时5h,最大吸附容量可达到60.24mg/g.     

铀在高岭土上的吸附动力学及热力学研究

采用静态法研究了铀(U(Ⅵ))在高岭土上的吸附特性,探讨了pH、离子强度、接触时间、温度、腐殖酸等对U(Ⅵ)在高岭土上吸附的影响.以宏观吸附实验为基础,对高岭土进行X线衍射(XRD)和扫描电镜(SEM)表征,并讨论了铀(U(Ⅵ))在高岭土上的吸附动力学及热力学行为.结果说明,准二级动力学模型可以用来描述铀在高岭土上的吸附.通过对溶液pH值和离子强度因素的研究,溶液pH值对铀的吸附影响比离子强度对铀的吸附影响更大.在较低pH值下,腐殖酸对吸附有加强的作用;在较高pH值下,腐殖酸对吸附有抑制作用.Freundlich模型可较好地描述高岭土对U(Ⅵ)的吸附过程.高岭土对U(Ⅵ)的吸附为自发且吸热的过程,主要是表面单分子层吸附.     

SiC表面负载Cu复合材料的制备与表征

基于工业碳化硅(SiC)微粉,采用化学改性法将铜负载于SiC原粉表面,使用扫描电子显微镜(SEM)、X-射线粉末衍射仪(XRD)和X-射线光电子能谱(XPS)等表征测试方法,分别考察了pH值、Cu负载量、分散介质等因素对改性实验的影响.结果显示:经高温煅烧后,Cu离子以CuO和Cu2O的氧化态形式负载于SiC表面;不同的分散介质、pH值和Cu离子负载量影响以氧化态形式负载到SiC表面的Cu离子分布.     

负载金属离子ZSM-5分子筛膜脱除苯并噻吩-二苯并噻吩的性能

采用水热合成法制备ZSM-5分子筛膜,并通过负载金属离子对其进行改性。通过X线衍射仪(XRD)、扫描电子显微镜(SEM)对所制备的膜进行表征。将所制得的ZSM-5分子筛膜经过负载金属离子改性后用于模拟汽油中苯并噻吩、二苯并噻吩二元硫化物的分离,考察负载离子种类、负载离子浓度和操作温度对二元硫化物竞争吸附和渗透通量的影响,并应用软硬酸碱理论(HSAB)分析吸附能力的强弱。结果表明:当Ag+浓度为0.2 mol/L时硫化物的分离因子最高可达1.31;随着操作温度的升高,ZSM-5分子筛膜渗透通量逐渐增大而分离因子逐渐减小。     

壳聚糖对铬(Ⅲ)离子吸附作用的研究

研究了壳聚糖对铬(Ⅲ)离子的吸附性能,测定了吸附等温线和吸附动力学曲线.实验结果表明壳聚糖对铬(Ⅲ)离子有较强的吸附能力.吸附率受pH值影响较大.在此基础上,通过IR、UV、SEM等检测手段证实铬(Ⅲ)离子与壳聚糖之间发生了配位作用.     

现场表面增强红外光谱法研究离子液体/电极界面结构

采用现场表面增强红外光谱法(SEIRAS)对金电极与离子液体1-丁基-3-甲基咪唑三氟甲基磺酸盐([Bmim][OTf])的界面电化学双电层结构进行了研究.循环伏安结果表明离子液体[Bmim][OTf]在金电极上的电化学窗口为4.0 V以上.SEIRAS结果显示阴阳离子在电极表面上发生脱吸附的电位区间以及阳离子和阴离子在电极表面上发生竞争的共吸附,同时阴阳离子在金电极界面上的脱吸附有显著的延迟效应产生,其原因与离子的表面吸附能和马德龙(Madelung)位能综合作用有关.     

铁负载膨润土对铀(VI)的吸附特性及机理研究

采用膨润土经提纯、钠化及负载铁等过程制备铁负载膨润土,通过静态吸附实验研究了pH、离子强度、吸附剂投加量、U（Ⅵ）初始浓度、阳离子Ca^2＋、Mg^2＋以及阴离子CO3^2-、HCO3^-等对铁负载膨润土吸附模拟废水中U（Ⅵ）的影响,进行了吸附过程动力学、热力学分析,并利用傅里叶红外光谱（FT-IR）、扫描电镜（SEM）探讨了相关吸附机理.试验结果表明,pH值和离子强度是影响吸附效果的重要因素,当溶液pH为6,离子强度为0.01 mol/L NaNO3,U（Ⅵ）初始浓度为19.08 mg/L,铁负载膨润土投加量为0.2 g/L,24 h吸附量达到88.06 mg/g.当pH〈6时,Ca^2＋、Mg^2＋、CO3^2-、HCO3^-的存在分别降低了铁负载膨润土对U（Ⅵ）的吸附效果,而pH〉7时影响作用不大.准二级动力学和Langmuir等温吸附模型对铁负载膨润土吸附U（Ⅵ）的拟合效果较好,SEM和FT-IR分析结果表明铁负载膨润土主要通过羟基络合及离子交换作用结合U（Ⅵ）进入其层间及表面.     

天然钠长石和钾长石对水溶液中氟吸附性能的研究

通过批实验研究了pH、初始氟离子浓度、反应时间和离子强度等因素对天然钠长石和钾长石吸附氟的影响.结果显示,钾长石和钠长石的pH_(pzc)分别为8.0和6.5,说明酸性条件更有利于长石矿物对氟的吸附,其中吸附反应最佳pH为3.初始氟离子浓度增大能够显著促进长石对氟的吸附,pH=2时,随着初始氟质量浓度从20 mg·L~(-1)增加到310 mg·L~(-1),钠长石对氟的吸附率从1.9%增加到29.4%,钾长石对氟的吸附率从2.8%增加到40.2%.长石对氟的吸附过程可以使用准二级动力学模型和Freundlich等温吸附模型所描述,离子强度对氟的吸附能力没有大的影响,说明吸附过程主要受化学吸附的控制.由于钾长石更大的比表面积和更多的吸附点位,酸性条件下钾长石对氟的吸附能力比钠长石更大.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with